The 43-year-old DeHaan filed papers in 2010 renouncing his U.S. citizenship and challenging government authority, and he claims to be a minister of the Native American Church of Nemenhah — which claims to be a “healing-based religion.”

But an attorney for the Native American Rights Fund described the church — which uses “sovereign citizen” tactics to challenge government authority — as nothing but “sham artists.”

Federal agents raided DeHaan’s home as part of a joint FBI/Internal Revenue Service investigation, and recently unsealed documents reveal a startling discovery beneath his front yard.

Agents said they discovered about 70 weapons, including high-powered rifles and ammunition, in a multi-room bunker, in addition to 10 more guns found inside DeHaan’s home and vehicles.

They also found food and beverages stored in the bunker, in addition to at least two 2,000-gallon water tanks, and materials investigators believe could be used to build a bomb — including including PVC piping, Tannerite, aluminum powder and 100 feet of fusing.

The underground bunker was outfitted with an air filtration system in case of a nuclear attack.

He also grew herbal remedies in the bunker, which he did not have a permit to build.

DeHaan avoided paying taxes since 1997 by claiming that his earnings were actually religious donations, but the IRS does not recognize Nemenhah as a tribe or a church.

He has been charged with tax evasion and attempting to interfere with administration of internal revenue laws.

His attorney described DeHaan, who held a passport issued by the World Government of World Citizens, as a “prepper” and gun collector.

Dehaan is not licensed by the state of North Carolina, and he’s not recognized by the North Carolina Association of Naturopathic Physicians.

“This is defrauding the public,” said Dr. Susan DeLaney, of the NCANP. “I mean really, would you go to see a mail order dentist?”